In one known solenoid valve, the space required and the electric power necessary for switching are relatively slight. This solenoid valve is, however, very expensive. Further reduction in the space required and the cost of such a valve have been limited by the fact that both the magnetic field of the electromagnet and the magnetic field of the permanent magnet must be developed asymmetrically since the magnetic flux of the permanent magnet must be conducted along an additional flux conducting element which is disposed on one arm of the U-shaped core of the electromagnet in order to mesh with the flux of the electromagnet. Furthermore, the U shape of the core of the electromagnet makes division thereof necessary if the exciter winding is to be inserted as a ready-wound coil.
Furthermore, in known solenoid valves there are structural difficulties in protecting the armature from contact with the fluid to be controlled by the solenoid valve, and the inert mass of the armature and its bearing friction are commonly relatively great.
An object of the present invention is to create a solenoid valve which, while taking up less space, can be made at lower cost. It is a further object of the invention to make it possible, without difficulty, to separate the armature from the fluid to be controlled.